1. Technical Field of the Invention
The present invention relates to safety closures for use on containers. More particularly, the present invention relates to a safety closure for use on a container wherein the safety closure is provided with means to prevent removal of the safety closure from the container.
2. Discussion of the Prior Art
The use of cooperating locking lugs on safety closures and containers to prevent individuals of tender age from gaining access to the contents of the container is relatively well-known in the prior art. Typically, a safety closure is provided including a flexible annular skirt having an inner annular surface thereof and a pair of opposed locking lugs projecting inwardly therefrom. A container is also provided with a container neck portion having on an exterior surface thereof a pair of opposed, outwardly-projecting locking lugs. The safety closure of this type is threadingly engageable on the container neck portion until the closure locking lugs pass over and beyond their respective cooperating container locking lugs, thereby causing interference therebetween and preventing removal rotation of the safety closure relative to the container neck. Removal of the safety closure from the container neck requires an individual to first overcome the interference between the cooperating locking lugs and to then concurrently apply sufficient removal rotation to the safety closure relative to the container. It is therefore desirable to provide a safety closure for use on a container wherein the safety closure is provided with locking lugs to prevent removal of the safety closure from the container.
For example, U.S. Pat. No. 3,941,268 to Owens, et al., teaches a safety closure and a container having cooperating locking lugs to prevent removal of the is safety closure from the container. More particularly, the locking lugs of the safety closure according to the Owens ""268 patent project inwardly from an inner surface thereof along a plane substantially perpendicular thereto. Even further, the container locking lugs project outwardly from an outer surface thereof along a plane substantially perpendicular thereto. As such, the cooperating locking lugs interfere along a plane substantially perpendicular to either the safety closure inner surface or the container outer surface. Accordingly, very little flexing thereof is required before the cooperating locking lugs xe2x80x9cskipxe2x80x9d over one another. It is thus desirable to provide a safety closure for use on a container wherein the safety closure and the container are provided with cooperating locking lugs to prevent removal of the safety closure from the container and wherein the respective locking lugs are angled sufficiently relative to one another to enhance the interference therebetween.
For example, U.S. Pat. No. 4,213,534 to Montgomery teaches a child-resistant closure for use on a container wherein the closure is provided with internal back-angled lugs for engaging cooperating back-angled lugs provided on the container. However, it is furthermore desirable to provide a safety closure for use on a container wherein the safety closure is provided with back-angled locking lugs respectively having a height which is less than the height of the closure.
For example, U.S. Pat. No. 2,423,582 to Coleman teaches a bottle cap for use on a container wherein the bottle cap includes internal back-angled tongues for engaging cooperating sloping lugs provided on the container and wherein the back-angled tongues of the bottle cap do not extend the full longitudinal height of the bottle cap. However, it is furthermore desirable to provide a safety closure for use on a container wherein the safety closure is provided with locking lugs having a shape which permits efficient molding thereof.
It is an object of the present invention to provide a safety closure for use on a container wherein the safety closure is provided with locking lugs to prevent removal of the safety closure from the container.
It is another object of the present invention to provide a safety closure for use on a container wherein the safety closure and the container are provided with cooperating locking lugs to prevent removal of the safety closure from the container and wherein the respective locking lugs are angled sufficiently relative to one another to enhance the interference therebetween.
It is yet another object of the present invention to provide a safety closure for use on a container wherein the safety closure is provided with back-angled locking lugs respectively having a height which is less than the height of the closure.
It is still yet another object of the present invention to provide a safety closure for use on a container wherein the safety closure is provided with locking lugs having a shape which permits efficient molding thereof.
A safety closure according to the present invention includes a top wall, an annular side skirt depending downwardly from an outer periphery of the top wall and defining a lower end thereof opposite the top wall, an internal thread projecting inwardly from an inner annular surface of the side wall, the internal thread being disposed towards the top wall, and at least one lug projecting inwardly from the side wall inner annular surface, the at least one lug defining an acute angle with the side wall inner annular surface, the at least one lug having a substantially trapezoidal profile, the substantially trapezoidal profile having a base edge disposed parallel to a central axis of the side wall and coincident therewith, a lower edge projecting inwardly from a lower end of the base edge, an inner edge parallel to the base edge and extending upwardly from an innermost end of the lower edge, and an angled edge connecting an upper end of the inner edge with an upper end of the base edge, the base edge upper end being vertically above the inner edge upper end.